It is often necessary to inspect and maintain areas under conditions that render them inaccessible or otherwise uninhabitable for humans for an extended period. These conditions include, for example, small confined spaces and harsh environments such as insufficient air/oxygen, presence of toxins, radioactivity, contamination, excessive dust, dirt and filth, and high noise levels. These conditions can be found, for example, in areas common to storm and sewer pipes, nuclear reactors and containment structures, fossil fuel plants and petrochemical refining facilities just to name a few. Although each area presents its own problems and complexities with respect to inspecting and maintaining, the inconvenient and time-consuming nature of performing an initial inspection is common to all.
For illustrative purposes, the inspection of storm and sewer pipes is considered in detail, although the scope of the present invention is by no means limited to this application. Most municipalities contain a vast network of storm and sewer pipes, often representing the oldest infrastructure in the community. Periodically, these pipes must be inspected for problems such as cracks, blockage, build-up, and root infiltration. To this end, it is common for an invasive device such as a pipe crawler or push camera to be introduced into the pipe to perform the inspection. Although effective in obtaining detailed images, using a pipe crawler is inconvenient and requires a great deal of time to set up and operate even if no problem is discovered. Furthermore, the use of pipe crawlers is frequently limited by the size and configuration of pipes to be entered. In this regard, often the condition of the pipe (e.g., debris and fractures) prevents the use of invasive inspection devices like crawlers. Therefore, there is a need for a more convenient approach to inspect and maintain underground pipes without the time and complexity associated with invasive techniques such as the use of pipe crawlers or push cameras.
This need has been fulfilled by the QuickView® inspection device commercially available from Envirosight LLC (Randolph, N.J.), and described in a series of patents and patent applications, starting with U.S. Pat. No. 6,538,732, incorporated herein by reference. The '732 patent describes a quick and convenient non-invasive approach to ascertain the condition of an inaccessible or uninhabitable area before initiating an invasive procedure such as a comprehensive inspection or cleaning. More specifically, rather than physically entering the area with a robotic or push camera, a highly-maneuverable, hand-held inspection system is provided having an imaging head which can be readily positioned to image the general area initially, and then to zoom in on a target to obtain its image with the desired degree of detail. Thus, the device obtains images of inaccessible or uninhabitable areas by maneuvering an imaging head and using its magnification capabilities, rather than by physically entering the area.
U.S. Pat. No. 7,480,041 (incorporated herein by reference) further advances this technology by improving the performance and maneuverability of the inspection device. Specifically, this patent discloses a system and method for improving inspection of lateral pipes by enabling the imaging head to focus on a target at longer range down a pipe than typically previously possible. This involves positioning the imaging head reliably in an optimum location with respect to the lateral pipe, referred to as the “sweet spot.” Generally, the optimum position is where the illumination source or lamp is positioned such that its light beam propagates down the pipe to the furthest extent possible before reflecting off the pipe wall and diffusing. The '041 patent discloses a targeting fixture to provide moderate resilient force as a user urges the imaging head into the sweet spot. The targeting fixture comprises, in one embodiment, a resilient member extending from the imaging head. In use, the inspection device is lowered into a manhole (or similar structure) until the targeting fixture rests on the bottom of a pipe (or similar structure). The user then pushes down on the imaging device until the imaging head is in the sweet spot. It has been found that pushing against the resilient targeting fixture provides a high degree of stability—essential during high magnification. Thus, the targeting fixture of the present invention enables the imaging head to be positioned in the sweet spot to achieve maximum illumination down the pipe, while providing enhanced stability for focusing on targets further down the pipe than previously possible.
US Patent Application Publication No. 20090180110 (incorporated herein by reference) further advances this technology by disclosing a long-range imaging system having an adjustable light beam. That is, this application recognizes that once a target is imaged down a pipe, slight adjustment of the lamp(s) while holding the imaged target steady can significantly improve the illumination of the target, and thus the quality of the image. This application also discloses the desirability of making the axis of the light beam coincident with the optical axis of the image device to maximize the illumination of the field of view.
While US Patent Application Publication No. 20090180110 recognized the need to have the axes of the light and the imaging device essentially coincident, the configuration disclosed therein necessarily involved an offset of the two axes because the lights were mounted to the side of the imaging device, thus necessitating some active adjustment of the light as the camera zoomed in and out. Therefore, there is a need for a simpler camera system in which the light axis and the imaging axis are essentially coincident without the need for active tuning as the device is zoomed in and out. The present invention fulfills this need among others.